Journal of Material Sciences & Engineering

Flame Spray Synthesis of WO₃ for No Breath Monitors

Abstract

Gouma PI and Wang L

The γ-phase polymorph of WO₃ has been established in the literature as a selective NO sensor. When processed at the nanoscale, this material shows high sensitivity to trace levels of NO gas. Thus, it is intended for use in breath monitors of NO in exhaled breath to diagnose asthma. Focusing on the economic and scalable synthesis of this material, this paper reports on the flame-spray processing of WO3 nanopowders of the monoclinic γ-phase. Structural and chemical characterization of as-sprayed and heat-treated nanopowders were carried out that revealed the conditions for tailored phase and particle size distribution suitable for the intended application of this material in breath-based diagnostics.